1. Field of the Invention
The present invention relates to a liquid discharge recording head included in a liquid discharge type recording apparatus.
2. Description of the Related Art
A liquid discharge type recording apparatus represented by an ink jet printer is provided with a liquid discharge recording head which discharges liquid droplets. FIGS. 8A and 8B are views illustrating the configuration of essential parts of a conventional liquid discharge recording head 200, FIG. 8A is an enlarged view of a seal part, and FIG. 8B is the sectional view taken along a section line 8B-8B illustrated in FIG. 8A. In the liquid discharge recording head 200, a recording element substrate 210 and a flexible wiring member 230 are attached to a supporting member 250. Discharge ports 211 (refer to FIG. 8A) and an electrode portion 212 are provided in close proximity with each other in the recording element substrate 210. The flexible wiring member 230 is provided with an opening 231 for allowing the recording element substrate 210 to be exposed therethrough, and a flying lead 232 electrically connected to the electrode portion 212. In the liquid discharge recording head 200, a void provided between the side surface of the recording element substrate 210, and the supporting member 250, i.e., the rear side of the flying lead 232 is filled with first sealant 221 with relatively low viscosity and flexibility. Additionally, an electrical connection that is a connection between the electrode portion 212 and the flying lead 232 is covered with second sealant 222 which has relatively high viscosity and has rigidity against an external force (refer to FIG. 8B). This protects the electrical connection from corrosion caused by ink and an external force (Japanese Patent Application Laid-Open No. 2001-130001). However, in the liquid discharge recording head 200, two kinds of sealants with different characteristics according to the difference between seal parts are used, which will cause an increase in material cost. Thus, a liquid discharge recording head for solving such a problem is suggested, and is disclosed in Japanese Patent Application Laid-Open No. 2007-055221.
FIGS. 9A and 9B are views illustrating the configuration of a liquid discharge recording head 100 described in Japanese Patent Application Laid-Open No. 2007-055221, FIG. 9A is a plan view illustrating the configuration of essential parts of the liquid discharge recording head 100, and FIG. 9B is a sectional view taken along a section line 9B-9B illustrated in FIG. 9A. In the liquid discharge recording head 100, a recording element substrate 110 and a flexible wiring member 130 are attached to a supporting member 150. Discharge ports 111 and an electrode portion 113 are provided adjacent to each other in the recording element substrate 110. The flexible wiring member 130 is provided with a flying lead 132, a device hole 134 for allowing the discharge ports 111 to be exposed therethrough, and a bonding hole 135 for allowing an electrical connection 114 to be exposed therethrough. A void (the rear side of the flying lead 132) provided between the recording element substrate 110 and the supporting member 150 is filled with sealant 121 with low viscosity and high fluidity. The electrical connection 114 that is a connection between the flying lead 132 and an electrode terminal 113 is covered with sealant 122. Since the bonding hole 135 and the device hole 134 are provided independently from each other when the sealant 122 is applied, the sealant 122 is dammed at the peripheral edge of the bonding hole 135 (refer to FIG. 9B). Therefore, even if the sealant 122 has the same low viscosity as the sealant 121 and has a high fluidity, the outflow of the sealant 122 to the discharge ports 111 can be prevented. Accordingly, sealing can be made only by one kind of sealant.
In the liquid discharge recording head, a reduction in the materials to be used is required for further cost reduction. However, in the liquid discharge recording head 100, in order to reliably seal the electrical connection 114 with sealant, an amount of sealant to fill the void provided between the side surface of the recording element substrate 110 and the supporting member 150 is needed. Accordingly, there is a danger that the sealing will become insufficient by simply reducing the amount of the sealant to be used.